1. Field of the Invention
This invention relates generally to audiovisual recording equipment, and, more particularly, to vehicle-mounted observation and recording systems for use in connection with law enforcement activities.
2. Background
Most persons are now familiar with the use by law enforcement personnel of in-car audiovisual recording devices. Such devices have proved useful in documenting traffic stops and other law enforcement activities. A typical in-car dash-mounted system includes a camcorder electrically connected by a cable to a system control unit. The system control unit is mounted in an out-of-the-way location in the vehicle and is interfaced with an operator accessible control panel. The control panel contains switches for managing the operation of the device.
To maintain the integrity of event recordings, especially for use in connection with criminal prosecutions and court proceedings, many systems incorporate security controls over certain camera functions. The security controls are administered by the system control unit. For example, to prevent recording over a previously taped segment the system control unit may be set to disable the camcorder""s rewind function. Other security control options are typically incorporated into the logic of the system control unit.
Limitations of the conventional systems become apparent when the camcorder is sought to be removed from the dash mount to record events away from the vehicle, such as accident or crime scenes, searches and seizures and the like. Many systems are exclusively for in-car use, and those systems that purport to have a removable camcorder are incapable of being effectively utilized outside the vehicle. One problem arises in detaching the camera from the dash mount and disconnecting it from the system control unit. When time is of the essence, it is frustrating for the operator to have to disengage the camcorder from an unfriendly dash mount coupling and to unscrew one or more cables connecting the camcorder to the system control unit. Once disconnected, the operator often finds that the camcorder""s battery is low or completely discharged. To further complicate matters, disconnecting the camcorder from the system control unit disables the unit""s supervisory control over camera functions, thus compromising the integrity of the recording.
It is thus an object of the present invention to provide a camcorder mounting and control system which allows for the quick and easy disconnection of the camcorder from the dash mount and from the system control unit.
It is a further object of the invention that supervisory control over camera functions be maintained even after the camcorder is disconnected from the dash mount.
It is another object of the invention to ensure that the camcorder""s battery remains charged for out-of-vehicle use.
These and other objects are achieved in a camcorder mounting and control system comprising a camera interface unit (termed a xe2x80x9ccamera boxxe2x80x9d) and mounting tray combination. The camera box contains a camera interface circuit board having a power transmit line and a battery charging voltage transmit line which each function as a bridge between an in-vehicle system control unit and a camcorder. The forward end of the circuit board is provided with a sliding fit electronic interface, e.g., an edge connector, which is accessible via a forward end opening on the camera box. The camera box is received in the special mounting tray which includes a quick disconnect adapter board having a first adapter electronic interface, e.g., an edge connector, complimentary to the circuit board electronic interface and, in electronic communication therewith, a second adapter electronic interface, e.g., a pin socket, for receiving a cable from the in-vehicle system control unit. The camcorder is easily disconnected from the mounting tray by sliding the camera box toward the rear of the mounting tray to disengage the circuit board electronic interface from the first adapter electronic interface.
The camera interface circuit board further includes control line interface connections to the camcorder, a control circuit electronically connected to the control line interface connections to provide secure camera function control for out-of-vehicle use, a detection circuit electronically connected to the power transmit line to sense the voltage being supplied over the power transmit line, and a transfer circuit for coordinating command and control of the camcorder as between the system control unit and the camera interface control circuit.
The transfer circuit is capable of assuming at least two positions in response to the detected voltage transmission across the power transmit line. In response to a first condition, namely the transmission across the power transmit line of a normal operating voltage supplied through the system control unit, the transfer circuit assumes a first position bypassing the control circuit on the camera interface circuit board so that camera function control is managed by signals emanating from the system control unit and passing over the control line interface connections to the camcorder. In response to a second condition, namely the lack of any appreciable voltage across the power transmit line, meaning that power is not being supplied to the camcorder through the system control unit, such as would be the case if the camcorder has been removed from the vehicle for exterior use, the transfer circuit assumes a second position enabling the on-board control circuit.
The on-board control circuit includes means for maintaining the secure control of camera functions when the camcorder is disconnected from the mounting tray, i.e., when the camcorder is being used outside the vehicle. Electronically connected to the control circuit are a power control switch and a multi-position camera function key switch, each located on the camera box for easy operator accessibility. When the camcorder is in the mounting tray and power is being supplied through the vehicle system control unit these switches are disabled, as, per the transfer circuit, the vehicle system control unit is then commanding camera function. The switches on the camera box are enabled by the transfer circuit once the detection circuit recognizes by a drop in voltage across the power transmit line that the camcorder has been removed from the mounting tray. The control circuit has alternate camera function control circuitry components responsive to the position of the camera box key switch. In the most preferred embodiment of the invention, the key switch has three positions. In response to the position of the key switch, the control circuit limits the operator selectable camera functions to, alternatively, a record only mode, a record/eject mode, and a playback mode. The key is removable from the key switch in any position so that an operator""s supervisor may select the appropriate mode and xe2x80x9clockxe2x80x9d it in by removing the key.
Once the camcorder is removed from the mounting tray, power is provided by the camcorder battery. Pressing the power control switch on the camera box turns on the camcorder. Battery charging circuitry in the system control unit operable during in-vehicle use ensures that the battery is always charged for out-of-car use.